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Diffstat (limited to 'results/classifier/108/performance/1857')
| -rw-r--r-- | results/classifier/108/performance/1857 | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/results/classifier/108/performance/1857 b/results/classifier/108/performance/1857 new file mode 100644 index 000000000..ffa6f04e0 --- /dev/null +++ b/results/classifier/108/performance/1857 @@ -0,0 +1,67 @@ +performance: 0.996 +device: 0.938 +socket: 0.916 +graphic: 0.901 +PID: 0.895 +debug: 0.861 +semantic: 0.842 +permissions: 0.841 +vnc: 0.817 +network: 0.817 +files: 0.779 +KVM: 0.713 +boot: 0.639 +other: 0.489 + +Major qemu-aarch64 performance slowdown since commit 59b6b42cd3 +Description of problem: +I have observed a major performance slowdown between qemu 8.0.0 and 8.1.0: + + +qemu 8.0.0: 0.8s + +qemu 8.1.0: 6.8s + + +After bisecting the commits between 8.0.0 and 8.1.0, the offending commit is 59b6b42cd3: + + +commit 59b6b42cd3446862567637f3a7ab31d69c9bef51 +Author: Richard Henderson <richard.henderson@linaro.org> +Date: Tue Jun 6 10:19:39 2023 +0100 + + target/arm: Enable FEAT_LSE2 for -cpu max + + Reviewed-by: Peter Maydell <peter.maydell@linaro.org> + Signed-off-by: Richard Henderson <richard.henderson@linaro.org> + Message-id: 20230530191438.411344-21-richard.henderson@linaro.org + Signed-off-by: Peter Maydell <peter.maydell@linaro.org> + + +Reverting the commit in latest master fixes the problem: + +qemu 8.0.0: 0.8s + +qemu 8.1.0: 6.8s + +qemu master + revert 59b6b42cd3: 0.8s + +Alternatively, specify `-cpu cortex-a35` to disable LSE2: + +`time ./qemu-aarch64 -cpu cortex-a35`: 0.8s + +`time ./qemu-aarch64`: 6.77s + +The slowdown is also observed when running qemu-aarch64 on aarch64 machine: + +`time ./qemu-aarch64 /usr/bin/node -e 1`: 2.91s + +`time ./qemu-aarch64 -cpu cortex-a35 /usr/bin/node -e 1`: 1.77s + +The slowdown on x86_64 machine is small: 362ms -> 378ms. +Steps to reproduce: +1. Run `time ./qemu-aarch64 node-aarch64 -e 1` (node-aarch64 is NodeJS v16 built for AArch64) +2. Using qemu master, the output says `0.8s` +3. Using qemu master with commit 59b6b42cd3 reverted, the output says `6.77s` +Additional information: + |